Google Cache of Different Site

[EliteWeb]

Hello Webmaster World.
I made a site for a client and to my surprise when I did cache snapshot of page it showed a URL and page of one of his other sites. This site wasn't hosted on my server, and none of the content is duplicated what could cause this. The backlinks even show the backlinks for his other site. Just his name triggered something?

[ciml]

Hello EliteWeb. This is what happens when Google finds identical content. Given the fact that both pages are owned by the same person, the chance of it being coincident with a very rare Google bug seems close to impossible.

I don't think it could be the domain name, maybe a redirect was in place during the crawl, just before the launch?